1207 Differences of Gastric Cancer Characteristics Between With and Without Helicobacter pylori Eradication

Abstract

INTRODUCTION: Although the rate of gastric cancer (GC) after Helicobacter pylori (H. pylori) eradication has gradually increased over time, the features of GC following eradication remain to be examined. In this study, we investigate the clinicopathological features of GC following eradication in comparison with those of GC with H. pylori infection. METHODS: 50 subjects with GC following eradication [HP(-) group] and 151 patients with GC with H. pylori infection [HP(+) group] were enrolled in this study. Clinicopathological features, such as age, gender, endoscopic atrophy, tumor form, location, depth of invasion, histology, were assessed. The manifestation of GC was further evaluated using immunohistochemistry of Ki-67, CDX22, p53, claudin18, E-cadherin, c-myc and In situ hybridization for detecting Epstein-Barr virus (EBV). RESULTS: Macroscopic analysis revealed a significantly higher ratio of depressed type/elevated type in HP(-) group compared with HP(+) group (30/19 vs. 61/77, P = 0.041). Tumor size was significantly greater in HP(-) group compared with the HP(+) group (13.02 ± 7.10 vs. 16.53 ± 11.12, P = 0.0019). The gastric mucin phenotype was more predominant in HP(-) group compared with HP(+) group, and the proportion of CDX2-positive cases was lower in HP(-) group (8 out of 18; 44.4%) compared with HP(+) group (18 out of 19; 94.7%) (P = 0.00082). Ki-67 labeling index was significantly lower in HP(-) group (32.03 ± 22.15) compared with the HP(+) group (79.20 ± 14.87, P < 0.0001). No patient in HP(-) group showed significant expression of EBV infection. CONCLUSION: The clinicopathological characteristics of GC following H. pylori eradication differ from those of GC in patients with H. pylori infection in morphology, mucin phenotype, and proliferation rate. It is necessary to be careful about these differences in GC screening.